1. Field of the Invention
The invention relates to powered surgical instruments. In particular, the invention relates to a handpiece to which a variety of surgical tools may be attached. Still more particularly, the invention relates to the method and apparatus by which the collet mechanism holding the tool may be attached to the handpiece and selectively adjustable, i.e. bendable, to one of a plurality of positions relative to the handpiece body.
2. Description of the Prior Art
Surgical handpieces for driving a variety of surgical tools are well known for both open and closed surgical procedures (i.e. endoscopic, arthroscopic, etc.). Such instruments generally comprise a powered handpiece having a distal end to which a variety of surgical tools may be attached by means of some chuck or collet mechanism. The handpiece receives power at its proximal end from any one of a number of sources (e.g. pneumatic, electric, battery) and contains a drive means for providing rotary (or other) power to the surgical tool. It is known to provide attachments for the distal tips of handpieces by which the various tools may be oriented at selected positions relative to the handpiece body. Generally, the axis of the tool is able to be placed by a user either in a position coaxial to the drive axis of the handpiece body, i.e. a straight orientation, or one or more other positions in which the tool axis intersects with but is angled relative to the drive axis of the handpiece body, i.e. an angled orientation. It will be understood that the term "drive axis" means the main axis along which power is transmitted (e.g. a rotating drive shaft), and as such handpieces having all configurations (pencil-type, pistol grip, etc.) will have such a drive axis.
Such adjustability of tool orientations is usually provided by fixed attachments interposed between the collet mechanism and the handpiece. For example, the Hall Ultrapower.RTM. Drill System manufactured by Linvatec Corporation, Largo, Fla. 33773 provides a variety of burr guards in various lengths and fixed angular orientations in order to enable a user to choose between using the tool in coaxial alignment with the handpiece or in a fixed angular orientation relative to the handpiece. However, because of the fixed nature of the angled burr guards, a user must have available both straight and angled attachments in order to have the flexibility of choosing a particular orientation at the time of surgery. It would be preferable, and it is an object of this invention, to enable the user to minimize the number of attachments that must be held in inventory while still enabling the user to select a particular tool orientation at the time of surgery.
It is also known to provide adjustability of tool orientation by a variable attachment interposed between the collet mechanism and the handpiece. One such device is shown in U.S. Pat. No. 636,476 (Webster) as embodied in a dental handpiece having the drill adjustable into a variety of positions relative to the handpiece body. The chuck mechanism in this device must be locked into a selected position by placing a retaining pin in corresponding apertures.
It is an object of this invention to produce a bendable collet mechanism for a powered surgical handpiece so that a surgical tool may be selectively placed into one of a plurality of positions relative to the handpiece body and automatically held in the selected position during use.
It is another object of this invention to provide such an adjustable collet mechanism which is usable without the necessity for other tools to lock or unlock the collet mechanism from any of its possible positions relative to the handpiece body.
It is also an object of this invention to provide a system for enabling a user to selectively choose between straight and angled tool orientations.